脱式计算 54÷[6.3-13/4×(12/3+19/21)]; 8.8÷21/5×(1.05÷31/2).
问题描述:
脱式计算
54÷[6.3-1
×(13 4
+2 3
)];19 21
8.8÷2
×(1.05÷31 5
). 1 2
答
①54÷[6.3-1
×(13 4
+2 3
)]19 21
=54÷[6.3-
×7 4
]18 7
=54÷[6.3-4.5]
=54÷1.8
=30;
②8.8÷2
×(1.05÷31 5
)1 2
=8.8÷2
×0.31 5
=4×0.3
=1.2.